U.S. stock futures swung between small gains and losses on Thursday, as investors tracked the affect of Hurricane Irma and focused on European Central Bank President Mario Draghi's news conference after the bank left interest rates unchanged.

ECB live blog: Is a strong euro making Mario Draghi miserable? (http://blogs.marketwatch.com/thetell/2017/09/07/ecb-live-blog-is-a-strong-euro-making-mario-draghi-miserable/)

Futures for the Dow Jones Industrial Average was little changed at 21,820, while those for the S&P 500 index were flat at 2,465.50. Futures for the Nasdaq-100 index also were steady at 5,957.

The major U.S. benchmarks closed higher on Wednesday (http://www.marketwatch.com/story/us-stock-futures-kept-in-check-by-worries-over-north-korea-hurricane-irma-2017-09-06) after congressional leaders and President Donald Trump agreed to extend the debt-limit deadline and fund the government through mid-December.

The agreement raised hopes for more bipartisan deals that would allow the Trump administration to move forward with its promised economic reforms. However, it also raised concerns that divisiveness in the Republican party may limit further policy success, because other GOP leaders weren't in favor of a short-term agreement.

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First Take:Trump's deal with 'Chuck and Nancy' may improve chances for his legislative agenda (http://www.marketwatch.com/story/debt-ceiling-deal-may-slightly-improve-chances-for-trump-agenda-2017-09-06)

Investors turned their attention to Category 5 Hurricane Irma that wrecked (http://www.marketwatch.com/story/death-toll-rises-to-8-as-hurricane-irma-barrels-through-caribbean-heads-for-florida-2017-09-07) a string of Caribbean Islands as it barreled toward the Florida coast. The weather system--the worst ever recorded in the Atlantic--is expected to hit the Miami area and the Florida Keys on Sunday, sparking a mandatory evacuation of the southern, coastal parts of the state.

Several people have died in Barbuda, St. Martin and Anguilla, according to media reports.

Irma comes just two weeks after Hurricane Harvey hit the Texas and Louisiana Gulf Coast, where damages are estimated by AccuWeather to be up to $190 billion (http://www.marketwatch.com/story/hurricane-harvey-could-cost-190-billion-be-worst-ever-us-natural-disaster-says-accuweather-2017-08-31).

Several airlines and cruise operators were forced to cancel flights and sailings, sending shares of some of the companies lower on Thursday in premarket trading. Shares of American Airlines Group Inc. (AAL) dropped 3.5% ahead of the bell, while Carnival Corp. (CCL) lost 0.4%.

Read:JetBlue and Delta offer special pricing to people fleeing Hurricane Irma (http://www.marketwatch.com/story/jetblue-and-delta-offer-special-pricing-to-people-fleeing-hurricane-irma-2017-09-06)

ECB in focus: The ECB left key interest rates unchanged and expects them to remain at present levels for "extended period". In the accompanying statement, which was virtually identical to the previous one, the central bank said that asset buying will continue at a EUR60 billion ($71 billion) a month through year-end or beyond and quantitative easing could be ramped up if the outlook deteriorates.

The euro strengthened against rivals after Draghi answered questions during the news conference, hitting $1.20 in early New York trade. That helped push the ICE Dollar Index down 0.8% to 91.566.

Read: Here's how the ECB got 'stuck in the euro trap' on its way to winding down QE (http://www.marketwatch.com/story/heres-how-the-ecb-got-stuck-in-the-euro-trapon-its-way-to-winding-down-qe-2017-09-05)

European stocks (http://www.marketwatch.com/story/european-stocks-hold-steady-in-runup-to-ecb-update-2017-09-07) trimmed earlier gains but were still slightly higher.

Economic news: Initial jobless claims in the period running from Aug. 27 to Sept. 2 surged by 62,000 to 298,000, reaching the highest level since spring 2015, largely due to Hurricane Harvey that left many Americans unable to work.

Among Federal Reserve speakers, Cleveland Fed President Loretta Mester is scheduled to address the economic outlook and monetary policy at the Economic Club of Pittsburgh, at 12:15 p.m. Eastern.

New York Fed President William Dudley will speak at New York University at 7 p.m. Eastern. Later, Kansas City Fed President Esther George will discuss the U.S. economic outlook at the Omaha Economic Forum in Omaha, Neb., at 8:15 p.m. Eastern.

Amazon.com Inc.(AMZN) inched higher in premarket trade after the online retailer said it plans to open a second headquarters somewhere in North America (http://www.marketwatch.com/story/amazon-begins-city-search-for-second-n-american-headquarters-plans-to-invest-over-5-billion-2017-09-07) that will house up to 50,000 employees and cost $5 billion to build and operate.

Facebook Inc.(FB) was also in focus after the company late Wednesday said it traced ad sales totaling $100,000 from Russian accounts (http://www.marketwatch.com/story/facebook-links-thousands-of-political-ads-to-russian-troll-farm-2017-09-06), some of which are likely linked to a troll farm in St. Petersburg called the Internet Research Agency.